Viewing archive of Wednesday, 22 October 2025

Daily bulletin on solar and geomagnetic activity from the SIDC

Issued: 2025 Oct 22 1231 UTC

SIDC Forecast

Solar flares

C-class flares expected, (probability >=50%)

Geomagnetism

Quiet (A<20 and K<4)

Solar protons

Warning condition (activity levels expected to increase, but no numeric forecast given)

	10cm flux	Ap
22 Oct 2025	130	007
23 Oct 2025	130	007
24 Oct 2025	132	007

Solar Active Regions and flaring

Solar flaring activity was low over the past 24 hours, with several C-class flares recorded. The largest flare was a C4.7 flare (SIDC Flare 5853), peaking on October 22 at 01:52 UTC, associated with SIDC Sunspot Group 675 (NOAA Active Region 4259; magnetic type alpha). There are currently eleven numbered active regions on the visible solar disk. Low flaring activity was also produced by SIDC Sunspot Group 674 (NOAA Active Region 4257; magnetic type beta) and by active regions behind the east limb. The remaining active regions are relatively simple (magnetic type alpha or beta) and did not produce any significant flaring activity. Solar flaring activity is expected to be low over the next 24 hours, with C-class flares probable and a small chance for M-class flares.

Coronal mass ejections

A fast halo coronal mass ejection (SIDC CME 583) was observed in SOHO/LASCO-C2 imagery starting at 20:24 UTC on October 21. The CME is directed primarily toward the northwest from Earth's perspective and was associated with type II and type IV radio emissions, detected at 20:07 UTC and 20:11 UTC, respectively. Analysis indicates that the source of the CME was located on the far side of the Sun and is not expected to arrive at Earth. No other Earth-directed coronal mass ejections (CME) have been detected in the available coronagraph imagery over the past 24 hours.

Coronal holes

A small equatorial negative polarity coronal hole (SIDC Coronal Hole 133) crossed the central meridian late on October 21. An associated high-speed stream may affect the solar wind environment near Earth from October 25.

Solar wind

Over the past 24 hours, the solar wind parameters (ACE and DSCOVR) reflected the waning influence of a high-speed stream (HSS). The solar wind speed decreased from around 520 km/s to 400 km/s. The interplanetary magnetic field remained weak, below 8 nT, and its southward component fluctuated between -4 nT and 6 nT. Solar wind conditions are expected to gradually return to a slow solar wind regime over the next days.

Geomagnetism

Geomagnetic conditions were quiet both globally and locally over Belgium (NOAA Kp: 1 to 2; K-Bel: 1 to 2). Mostly quiet geomagnetic conditions are expected over the next 24 hours.

Proton flux levels

The greater than 10 MeV proton flux, as measured by GOES-18, began to increase from 00:00 UTC on October 22, likely due to the fast halo coronal mass ejection (SIDC CME 583), that was observed in SOHO/LASCO-C2 coronagraph data starting at around 20:24 UTC on October 21, but has remained below the 10 pfu threshold. The greater than 10 MeV GOES proton flux is expected to remain slightly elevated with a chance of exceeding the minor storm levels in the coming days.

Electron fluxes at geostationary orbit

The greater than 2 MeV electron flux measured by GOES 18 and GOES 19 was below the 1000 pfu threshold. The greater than 2 MeV electron flux is expected to remain below the 1000 pfu threshold over the next 24 hours. The 24-hour electron fluence was at normal levels and is expected to be at normal levels over the next 24 hours.

Today's estimated international sunspot number (ISN): 110, based on 10 stations.

Solar indices for 21 Oct 2025

Wolf number Catania	143
10cm solar flux	133
AK Chambon La Forêt	012
AK Wingst	012
Estimated Ap	011
Estimated international sunspot number	124 - Based on 16 stations

Noticeable events summary

Provided by the Solar Influences Data analysis Center© - SIDC - Processed by SpaceWeatherLive

All times in UTC

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